Changing Null Levels (-999) to Zero level for multiple points in a string

Hi All,

I am using MXRoad SS2.

I was trying to change null levels of few points in a string to zero level.

By using minor option 021/022 I was able to do that, but I can do that for single point at a time.

How to change ALL null levels in a string to zero level on one go. The string is having points with other level also, which I dont want disturb.

Thanks in advance.

Regards

Anil